Phase motion detector for baseband yc separation

ABSTRACT

Systems and methods are disclosed herein for a motion detection system for video signal processing that includes a luminance motion detector, a chroma motion detector, and a smoothness detector. These systems and methods may also include a phase motion detector, a baseband YC separation circuitry for video signal processing, a chip for video signal processing, and a video signal processing system used in an electronic article.

CROSS-REFERENCE TO RELATED APPLICATION(S) AND CLAIM OF PRIORITY

This application claims the benefit under 35 U.S.C. §119(a) to aSingapore patent application filed in the Intellectual Property Officeof Singapore on Dec. 31, 2008 and assigned Serial No. 200809671-1, theentire disclosure of which is hereby incorporated by reference.

TECHNICAL FIELD OF THE INVENTION

The present invention generally relates to video signal processing, andmore particularly to a phase motion detector for baseband YC separationfor image quality improvement.

BACKGROUND OF THE INVENTION

In composite video television systems such as NTSC and PAL, luminanceand chrominance information share a portion of the total signalbandwidth. While clean separation between luminance and chrominance ishighly desired, current video signal decoders misinterpret the sharedluminance and chrominance information, resulting in cross color and dotcrawl. Both are highly disturbing artifacts. The term “cross color”refers to corruption of the chrominance spectrum caused by themisinterpretation of high-frequency luminance information as chrominanceinformation. Cross color manifests itself in spectrum of bright colorschanging from frame to frame. Conversely, the term “dot crawl” or “crossluminance” refers to corruption of the luminance spectrum by themisinterpretation of chrominance information as high-frequency luminanceinformation. Dot crawl manifests itself in patterned high amplitudenoise.

Both artifacts can be reduced by selectively filtering video signalsduring signal processing. The filtering process usually employs a 3Dcomb filter comprising at least one line comb filter and at least oneframe comb filter. A line comb filter can reduce such artifacts but itseffectiveness is limited to artifacts generated by vertical edges and ithas a disadvantage of decreasing the vertical resolution. A frame combfilter, on the other hand, provides maximum picture resolution but canonly be applied to stationary parts of a picture. To maximize theeffectiveness of the comb filters, a highly precise motion detector thatcan differentiate between the moving and stationary pixels is required.

Conventional arts use a low pass inter-frame difference to generate amotion map to select line comb filters when motion is detected and framecomb filters when there is no motion. Depending on the cut-off frequencyof the low pass filter, the performance of the 3D comb filter varies. Ifthe cut-off frequency is high, some motion due to cross luminance may befalsely detected and the 3D comb filter's effectiveness is reduced. Ifthe cut-off frequency is low, motion with higher frequency content maynot be detected and motion smearing results. The higher the overlappingof the chrominance with video bandwidth, the more ineffective the motiondetection.

Some have improved the performance of motion detection by associatingoblique correlation with likelihood of false motion. One disclosedmotion detection device including an oblique correlation detectionsection, motion detection section and motion determination sectiondecreases the sensitivity of motion detection in the presence of anoblique correlation. However, the implementation of the concept usingdecreased sensitivity in presence of oblique correlation is notsufficient because of the conflict of interests. On one hand, thedecreased sensitivity may have impaired the detection of true motion foroblique objects. On the other hand, decreased sensitivity may not besufficient to prevent false motion detection in mixed color/luminanceedges since cross luminance are typically of large amplitudes.

Another example for motion detection uses a plurality of temporal pixelsto determine the motion or still status of the video composite signalsuitable for use in a 3D comb filter in video decoder. Yet anotherexample for motion detection uses a motion detection circuitry withprecise Y motion and C motion detection. The Y motion detection uses theframe difference of line-comb Y signal with chroma level and verticaledge consideration. The C motion detection uses the frame difference ofline-comb C signal, together with the frame difference of compositesignal and chroma vertical and horizontal correlation computed from theframe-comb Y signals of adjacent lines. Yet another example for motiondetection uses a two-frame difference signal that has been filtered toremove chrominance information. The filtering is performed on at leastone spatial axis according to the spatial correlation. Although thismotion detection considers the contributions from both luminance andchroma, it does not represent the temporal difference between the framesbeing filtered.

FIG. 13 shows an exemplary functional block diagram of a motion detectorof a conventional 3D comb filter. As to the NTSC standard, anapproximate luminance data is obtained after the composite video signalhas passed through a low pass filter, and a luminance data of theprevious frame is obtained after the approximate luminance data has beendelayed by a frame buffer for a frame time. The luminance data of thecurrent frame is then compared with the luminance data of the previousframe so as to obtain a luminance difference. In addition, a chrominancedata is obtained after the composite video signal has passed through aband pass filter and has been subtracted from the luma data. Then thechrominance data of the previous two frames is obtained after thechrominance data has been delayed by the frame buffers for two frametime. A chrominance difference is obtained after the chrominance data ofthe current frame is subtracted from the chrominance data of theprevious two frames. A detecting circuit calculates a motion factor byselecting a number which is bigger between the luminance difference andthe chrominance difference.

Generally, these methods do not consider motion contributed by chromacomponent because of interfering high frequency luminance at chromaband. However, certain types of motion exist with purely color motionand a misdetection results in color smearing.

Hence, there is a need to detect true luminance and chroma motions,especially chroma-only motion and high frequency luminance motion.Furthermore, the motion detection problem in baseband is morechallenging than in composite domain in that there are 3 corruptedcomponent inputs not guaranteed to be generated by complementarydecoders.

SUMMARY

In one embodiment of the present disclosure, there is provided a motiondetection system that detects all types of motions including highfrequency luminance motion and chroma motion independent of other signalprocessing. The motion detection system may comprises a luminance motiondetector detecting the low frequency luminance changes, a chrominancemotion detector for detecting the chroma changes, and a smoothnessdetector detecting the flat regions in chroma component. These systemsand methods may further comprise a phase motion detector detecting thehigh frequency luminance and chroma changes and outputting the resultsof the detection into a video processing unit or other device.

Other technical features may be readily apparent to one skilled in theart from the following figures, descriptions, and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments according to the present disclosure will now bedescribed with reference to the Figures, in which like referencenumerals denote like elements.

FIG. 1 is a functional block diagram of the circuitry of the motiondetection system for the NTSC standard in accordance with one embodimentof the present disclosure;

FIG. 2 shows exemplary electric circuitries for the luminance motiondetector 101, the chrominance motion detectors 102/103, the smoothnessdetectors 104/105, and the phase motion detectors 106/107 in accordancewith one embodiment of the present disclosure;

FIG. 3 shows an exemplary circuitry of the motion detector for NTSCstandard in accordance with another embodiment of the presentdisclosure;

FIG. 4 is a functional block diagram showing a baseband YC separationcircuitry in accordance with one embodiment of the present disclosure;

FIG. 5 shows an exemplary circuit of the cross luminance suppressioncircuit 2001 for the NTSC standard in accordance with one embodiment ofthe present disclosure;

FIG. 6, there is provided an exemplary circuit of the cross chromasuppression circuits 2002/2003 in accordance with one embodiment of thepresent disclosure;

FIG. 7 is a functional block diagram of a video signal processing systemin accordance with one embodiment of the present disclosure;

FIG. 8 is a functional block diagram of the circuitry of the motiondetection system for the PAL standard in accordance with one embodimentof the present disclosure;

FIG. 9 shows exemplary electric circuitries for the luminance motiondetector 1101, the chrominance motion detectors 1102/1103, thesmoothness detectors 1104/1105, and the phase motion detectors 1106/1107in accordance with one embodiment of the present disclosure;

FIG. 10 shows an exemplary circuit of the motion detector for PALstandard in accordance with another embodiment of the presentdisclosure;

FIG. 11 shows an exemplary circuit of the cross luminance suppressioncircuit 2001 in the baseband YC separation circuitry 2000 as shown inFIG. 4 for PAL standard in accordance with one embodiment of the presentdisclosure;

FIG. 12 shows an exemplary circuit of the cross chroma suppressioncircuits 2002/2003 in the baseband YC separation circuitry 2000 as shownin FIG. 4 for PAL standard in accordance with one embodiment of thepresent disclosure; and

FIG. 13 shows a functional block diagram of a motion detector.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The present disclosure may be understood more readily by reference tothe following detailed description of certain embodiments of thedisclosure. Throughout this disclosure, where publications arereferenced, the disclosures of these publications are herebyincorporated by reference in their entireties into this application inorder to more fully describe the state of art to which this disclosurepertains.

While embodiments of the present disclosure will be described inreference to the accompanying drawings, the specifics and details areprovided for the sole purpose of illustrating selected embodiments ofthe present disclosure. It is to be appreciated that the presentdisclosure may be practiced without employing the specifics and details.Furthermore, certain variations of the specifics and details in thepractice are permissible without deviation from the scope of theappended claims.

As illustrated in FIG. 1, there is provided a functional block diagramof the circuitry of the motion detection system for the NTSC standard inaccordance with one embodiment of the present disclosure. The motiondetection system 100 comprises a luminance motion detector 101 thatdetects low frequency luminance motion between frame n and n−1;chrominance motion detectors 102/103 that detect U and V chroma motionbetween frame n and n−1 respectively; smoothness detectors 104/105 thatdetect presence of luminance residue on U and V chroma components inframe n and n−1 respectively; phase motion detectors 106 and 107 thatdetect average luminance and chroma motion between frames n, n−1, n−2and n−3; and chroma motion combiner 108 that integrates the motionsderived from U and V components. The motion detection system 100 furthercomprise a Max 606, a saturation circuit 607, and a 5H-max circuit 608,which functions will be described in detail hereinafter. The saturationcircuits clip an input signal to a defined output range, and the 5H-maxcircuit chooses the maximum value of 5 consecutive pixels in ahorizontal window.

With reference to FIG. 2, there are provided exemplary electriccircuitries for the luminance motion detector 101, the chrominancemotion detectors 102/103, the smoothness detectors 104/105, and thephase motion detectors 106/107 in accordance with one embodiment of thepresent disclosure.

The luminance motion detector 101 detects precisely changes in theluminance component between frame n and frame n−1 used for the framecomb in NTSC standard. The input signal is vertically filtered to removechroma residue, to present the best-case line-comb Y signal fordifference computation. The output signal is low-pass filtered toeliminate the possibility of chroma component corruption at highfrequency.

The luminance motion detector 101 receives three line signals from eachof the current frame n and the previous frame n−1. For the current framen, the three line signals are the next line signal Y_(m+1,n) currentline signal Y_(m,n), previous line signal Y_(m−1,n) via two luminanceline delay memories, where m denotes the line number. A vertical lowpass filter 201 with coefficients [1 2 1]/4 is used to cancelout-of-phase chroma signal to generate line-comb signal YLC_(n).Concurrently, the luminance motion detector 101 also receives three linesignals from the previous frame n−1: next line signal Y_(m+1,n−1),current line signal Y_(m,n−1) and previous line signal Y_(m−1,n−1), viaone luminance frame delay memory and two additional luminance line delaymemories. Similarly, a vertical low pass filter 202 is used to generateline-comb signal YLC_(n−1). The line-comb signals YLC_(n) and YLC_(n−1)may alternatively be the output of line combs of the baseband circuitry.

These line-comb signals YLC_(n) and YLC_(n−1) are then subtracted by asubtractor 203. A horizontal low pass filter 204, with low passfrequency characteristics not exceeding the lower end of the overlappingfrequency band of chroma and luminance signal or band-stop frequencycharacteristics covering the chroma band, subsequently filters theline-comb signal differences to exclude possible interference of chromaresidue. The magnitude is extracted by an absolute circuit 205 andpassed through a coring circuit 206 to eliminate possible noiseinterference. Finally, the magnitude is multiplied by a multiplier 207with gain, YGain (G1), and clipped by a saturation circuit 208 toappropriate motion range to generate low frequency luminance motion YMn.

The chroma motion detectors 102/103 detect precisely changes in thechroma components between frame n and frame n−1 used for frame comb inNTSC standard. The input signal is vertically filtered to removeluminance residue, to present best case line-comb C signal fordifference computation. While each chroma component U or V is processedindependently by the chrominance motion detectors 102/103 to generatechroma motions UD and VD, the operations for each chroma component arethe same; thus for the sake of convenience, CD is used to referinter-changeably to either UD or VD in this document.

Similar to the luminance motion detector 101, the chrominance motiondetector 102/103 receives three line signals from each of the currentframe n and previous frame n−1. For the current frame n, the three linesignals are next line signal C_(m+1,n), current line signal C_(m,n),previous line signal C_(m−1,n) via 2 chroma line delay memories. Avertical low pass filter 301 with coefficients [1 2 1]/4 is used tocancel out-of-phase luminance signal to generate line-comb signal,CLC_(n). Concurrently, the chrominance motion detector 102/103 receivesthree line signals from the previous frame n−1: next line signalC_(m+1,n−1), current line signal C_(m,n−1), and previous line signalC_(m−1,n−1) received via one chroma frame delay memory and two chromaline delay memories. The line signals are vertically filtered by avertical low pass filter 302 to generate line-comb signal, CLC_(n−1).The signals CLC_(n) and CLC_(n−1) may be the output of line combs in abaseband circuitry discussed in detail hereinafter.

These line-comb signals CLC_(n) and CLC_(n−1) are then subtracted by asubtractor 303. Its magnitude is extracted by an absolute circuit 304 togenerate intermediate chroma motion CD_(p), low pass filtered by ahorizontal low pass filter 305 to smoothen transitions, and passedthrough a coring circuit 306 to eliminate possible noise interference.Finally, the magnitude is multiplied by a multiplier 307 with gain,CGAIN (G2), and clipped by a saturation circuit 308 to appropriatemotion range to generate chroma motion CD.

The smoothness detector 104/105 detects the presence of luminanceresidue in chroma components. The detector uses a constructivephase-subtraction diagonally within field and temporally between frame nand frame n−1 used for frame comb in NTSC standard. A null outputindicates flat region and accuracy of the chroma motion detector102/103. While each chroma component U or V is processed independentlyby smoothness detector to generate high frequency signal UF and VF, theoperations for each chroma component are the same; thus for the sake ofconvenience, CF shall refer interchangeably to either UF or VF in thisdocument.

As the chroma motion may be influenced by luminance residue in chromasignal, it is desirable to differentiate between true and false chromamotion. The smoothness detectors 104/105 detect the presence ofluminance residue and invalidate or override the output of respectivechrominance motion detectors. The smoothness detectors 104/105 receivethe same input as the chrominance motion detector 102/103: next linesignal C_(m+1,n), current line signal C_(m,n), and previous line signalC_(m−1,n) for current frame n; next line signal C_(m+1,n−1), currentline signal C_(m,n−1), and previous line signal C_(m−1,n−1) for previousframe n−1.

The smoothness detectors 104/105 include both forward and backwarddiagonal contributions. The line signals of current and previous framesare diagonally filtered by forward diagonal high pass filters 401/402,and backward diagonal high pass filters 403/404 with common coefficients[−1 2−1]/4. The input vector for forward diagonal contribution is[C_(x−1,m+1) C_(x,m) C_(x+1,m−1)] while the input vector for backwarddiagonal contribution is [C_(x−1,m−1) C_(x,m) C_(x+1,m+1)] where x isthe horizontal position of the pixel. The forward diagonally filteredsignals are subtracted by a subtractor 405 and its magnitude isextracted by an absolute circuit 407. The backward diagonally filteredsignals are subtracted by a subtractor 406 and its magnitude isextracted by an absolute circuit 408. A max circuit 409 selects themaximum of the forward or backward contribution to generate anintermediate high frequency signal CF_(p). The CF_(p) is filtered by ahorizontal low pass filter 410 to smooth transitions and then cored by acoring circuit 411 to eliminate small noise. A gain SmoGain (G3) via amultiplier 412 is multiplied to the filtered output, and the signal isclipped by a saturation circuit 413 to generate high frequency signalCF. Alternatively, circuits 410-413 may be replaced by binarythresholding circuit to output 0 in presence of flat region and 1 inpresence of luminance residue.

The phase motion detectors 106/107 detect the luminance and chromachanges from the temporally co-located pixels in chroma components. Thechanges are made independent of luminance residue in chroma byconsidering the phase relationship of the interleave signal. Chromapixels from current frame n(C_(n)), and three previous frames n−1(C_(n)−1), n−2 (C_(n)−2), and n−3 (C_(n)−3) in NTSC standard are used todetermine motion according to the following equation (1):

YCD=Max{|C _(n) +C _(n−1) −C _(n−2) −C _(n−2) −C _(n−3) |,|C _(n) −C_(n−1) −C _(n−2) +C _(n−3)|}  (1)

From one perspective, the first component gives the average chromamotion between frame n and n−2 while the second component measures theaverage luminance motion between frame n and n−2. From anotherperspective, the first component gives the difference in luminancemotion between frame n and n−1 and frame n−2 and n−3 while the secondcomponent gives the difference in chroma motion between frame n and n−1and frame n−2 and n−3.

While each chroma component U or V is processed independently by thephase motion detectors 106/107 to generate YC motion signal YUD and YVD,the operations for each chroma component are the same; thus for the sakeof convenience, YCD shall refer inter-changeably to either YUD or YVD inthis document.

The phase motion detectors 106/107 detect mainly chroma motion in thepresence of luminance residue and high frequency luminance motion. Thephase motion detectors 106/107 receive the current frame signal,C_(m,n), and a plurality of previous frame signals C_(m,n−1), C_(m,n−2),and C_(m,n−3), via three chroma frame delay memories. Then theintermediate motion values YCD_(p) is computed via a circuit 501according to the equation (2) below:

YCD_(p)=Max{C _(m,n) +C _(m,n−1) −C _(m,n−2) −C _(m,n−3) |,|C _(m,n) −C_(m,n−1) −C _(m,n−2) −C _(m,n−3)|}  (2)

The motion values may be smoothed by a horizontal low pass filter 502and cored through a coring circuit 503. It may be scaled by gainPhaseGain (G4) via a multiplier 504 and clipped by a saturation circuit505 to generate YC motion signal, YCD. The same phase motion detector106/107 may be applied on the luminance component to generate YC motionvalues according to the equation (3) below.

YYD_(p)=Max{Y _(m,n) +Y _(m,n−1) −Y _(m,n−2) −Y _(m,n−3) |,|Y _(m,n) −Y_(m,n−1) −Y _(m,n−2) −Y _(m,n−3)|}  (3)

In this case, the phase motion detector can complement detection of highfrequency luminance that may not be present as luminance residue inchroma signal. As each of the above detectors has its advantages andlimitations, they are combined constructively to give measures of motionbetween the frames to be filtered. Now referring back to FIG. 1, thechroma combiner 108 combines results from independent detectors with Uor V inputs. In the case of 4:2:2 sampling format, the samples ofindependent chroma is half that of luminance. The maximum chroma motionUD and VD is taken and duplicated corresponding to 2 luminance samplesby a maxD circuit 601 to give C2D. Similarly, the maximum high frequencysignal UF and VF is taken and duplicated by a maxD circuit 602 to giveC2F and the maximum YC motion YUD and YVD is taken and duplicated by amaxD circuit 603 to give YC2D. Thus, the duplicated signals have thesame sample rate as luminance motion.

To suppress false chroma motion detected from luminance interference ortemporally averaged motion, signals C2D and YC2D pass through a maxcircuit 604. The output is further modified by a selector 605. Outputfrom the max circuit 604 is selected when flat chroma region is detectedor C2F=0 and signal YC2D is selected in presence of luminance residue orC2F #0 to give signal CM. This compensates for undetected chroma motionby phase motion detector due to averaging effect in phase motiondetector.

The final motion value, K_motion, is derived as the maximum 606 betweenthe motion detected from luminance YM and motion detected fromchrominance CM, clipped by a saturation circuit 607, and furtherprocessed as the maximum in a 5-pixel horizontal window by 5H-maxcircuit 608.

Referring to FIG. 3, there is provided an exemplary circuitry of themotion detection system for NTSC standard in accordance with anotherembodiment of the present disclosure. Instead of combining the outputsof U and V detectors in the chroma combiner 108 as shown in FIG. 1, theintermediate output signals are combined before the filtering, coring,scaling and saturation processes. Intermediate chroma motions UDp andVDp are generated as before and combined either by simply interleavingUV or taking the maximum of UV and duplicating result via a maxD circuit701. The intermediate signal, C2Dp, is passed through a horizontal lowpass filter 702, coring circuit 703, scaling circuit 704 and saturationcircuit 705 to generate combined chroma motion C2D.

Intermediate chroma high frequency signals UF_(P) and VF_(P), aregenerated via plurality of diagonal filters and subsequently combinedeither by simply interleaving UV or taking the maximum of UV andduplicating result via a maxD circuit 801. The intermediate signal,C2F_(P), is passed through a horizontal low pass filter 802, coringcircuit 803, scaling circuit 804 and saturation circuit 805 to generatecombined high frequency signal C2F. Alternatively, signal C2Fp may bebinary thresholded to output C2F=0 in presence of flat region and C2F−Xin presence of luminance residue.

Likewise, intermediate YC motion signals YUDp and YVDp are generatedthrough an arithmetic circuit 901 and combined either by UV interleavingor duplicating maxd motion by the circuit 901. The output signalYC2D_(p) that is subsequently processed by a horizontal low pass filter902, coring circuit 903, scaling circuit 904 and saturation circuit 905to generate combined YC motion signal YC2D.

The various signals C2D, C2F and YC2D are combined through a selectorcircuit 1002 that selects YC2D when luminance residue is detected or themaximum of C2D and YC2D via a max circuit 1001 when flat chroma regionis detected, according to control signal C2F.

Referring to FIG. 4, there is provided a functional block diagramshowing a baseband YC separation circuitry in accordance with oneembodiment of the present disclosure. As shown in FIG. 4, the basebandYC separation circuitry 2000 comprises a cross luminance suppressioncircuit 2001 that suppresses dot crawl artifacts or chroma residuepresent in Y signal, a cross chroma (U) suppression circuit 2002 thatsuppresses cross colour artifacts or luminance residue present in Usignals, a cross chroma (V) suppression circuit 2003 that suppressescross colour artifacts or luminance residue present in V signals, and abaseband motion detector 2004 that differentiate between the moving andthe stationary pixels such that the optimum comb filter can be selectedto maximize effectiveness of YC separation. The baseband YC separationcircuitry 2000 receives Y_(in), U_(in) and V_(in) input signalsseparately and outputs the clean Y_(out), U_(out), and V_(out), signals.The operation of such a baseband motion detector 2004 has been describedabove.

Referring to FIG. 5, there is provided an exemplary circuit of the crossluminance suppression circuit 2001 for the NTSC standard in accordancewith one embodiment of the present disclosure. A wideband filter 2101with frequency response modeling the chroma band in composite signal andcomplementary to the horizontal filter 204 shown in FIG. 1 filters outthe low and high frequency signal and retains only the frequency bandwith interleave Y and C signal. The line comb 2102 removes the redundantchroma residue from the Y signal. It has a 3 line input, next lineY_(m+1,n,wbp), current line Y_(m,n,wbp) and previous line Y_(m−1,n,wbp).The inter-line differences are computed by subtractors 2103 and 2104 andsubsequently mixed by a mixer 2105 corresponding to K_(—)2D signal fromthe inter-line correlator 2106 described hereinafter.

The inter-line correlator 2106 detects the relative chroma correlationbetween the current and next line and current and previous line, suchthat the line comb does not filter across contrasting colour regions.The Y signal passes through the narrowband filter 2107 to isolate thesub-band of the YC interleave frequency band. The narrowband filter hasa smaller bandwidth centered at chroma subcarrier frequency of 3.58 MHzcompared to the wideband filter for purposes of less interference fromluminance signal. The gradients of current and next line, G_(x,m,m+1),and current and previous line, G_(x,m,m−1) are computed in gradientcircuits 2108 and 2109 using band-passed Y signal represented by Y forsimplicity according to the following equations (4-5) or (6-7).

G _(x,m,m+1)=min{max{|Y _(x,m+1) −Y _(x+2,m) |,|Y _(x+2,m+1) −Y_(x,m)|},max{|Y _(x,m+1) −Y _(x−2,m) |,|Y _(x−2,m+1) −Y _(x,m)|}}  (4)

G _(x,m,m−1)=min{max{|Y _(x,m−1) −Y _(x+2,m) |,|Y _(x+2,m−1) −Y_(x,m)|},max{|Y _(x,m−1) −Y _(x−2,m) |,|Y _(x−2,m−1) −Y _(x,m)|}}  (5)

G _(x,m,m+1)={max{|Y _(x+1,m+1) −Y _(x−1,m) |,|Y _(x−1,m+1) −Y_(x+1,m)|}  (6)

G _(x,m,m−1)={max{|Y _(x+1,m−1) −Y _(x−1,m) |,|Y _(x−1,m−1) −Y_(x+1,m)|}  (7)

They are subsequently filtered by horizontal low pass filters 2110 and2111 for continuity. The lower the gradient, the higher the correlation,meaning a higher possibility that the pixels from the two lines belongto the same colour region. Thus line-comb output from two lines having alower gradient should have a higher contribution towards the final combvalue. K_(—)2D is defined as the weight for the line comb filter betweenthe current and previous line in the function circuit 2112. K_(—)2D isrepresented by the equation (8) below.

K _(—)2D=(G′ _(m,m+1))/(G′ _(m,m+1) +G′ _(m,m−1))  (8)

Alternatively, K_(—)2D can be obtained from the K_(—)2D values generatedby the cross chroma suppression circuits 2002 and 2003. An examplemethod of combining may be represented by the equation (9) below:

K _(—)2D=(GU′ _(m,m+1) +GV′ _(m,m+1))/(GU′ _(m,m+1) +GV′ _(m,m+1) +GU′_(m,m−1) +GV′ _(m,m−1))  (9)

where GU′_(m,m+1) represents the low pass filtered gradient between thecurrent and next line for chroma signal U, GV′_(m,m+1) represents thelow pass filtered gradient between the current and next line for chromasignal V, GU′_(m,m−1) represents the low pass filtered gradient betweenthe current and previous line for chroma signal U, and GV′_(m,m−1)represents the low pass filtered gradient between the current andprevious line for chroma signal V.

The output of the line comb filter can be expressed according to theequation (10) below:

Y _(—)2D=K _(—)2D*(Y _(m) −Y _(m−1))+(1−K _(—)2D)*(Y _(m) −Y_(m+1))  (10)

The frame comb subtracts the previous frame signal Y_(m,n) from thecurrent frame signal Y_(m), using subtractor 2113 to generate frame comboutput Y_(—)3D.

The residual chroma signal is extracted via a mixer circuit 2114 usingmotion value, K_motion from the baseband motion detector 2004 and thefinal clean luminance signal, Y_(out) is generated according to theequation (11) below by subtracting the residual chroma signal from inputluminance signal, Y_(in), with a subtractor 2115 and clipping the outputto defined pixel range with a saturation circuit 2116.

Y _(out) =Y _(m)−(K_motion*Y _(—)2D+(1−K_motion)*Y3D)  (11)

Referring to FIG. 6, there is provided an exemplary circuitry of thecross chroma suppression circuits 2002/2003 in accordance with oneembodiment of the present disclosure. The architecture of the crosschroma suppression circuit is almost similar to the cross luminancesuppression circuit. The differences are the absence of the widebandfilter for line comb and narrowband filter for inter-line correlator.

The chroma line comb 2202 removes the redundant luminance residue fromthe Uin or Vin signal. Signal C shall be referring to either signal U orV for the cross chroma suppression circuit. It has a three line input,next line C_(m+1,n,wbp) current line C_(m,n,wbp) and previous lineC_(m−1,n,wbp). The inter-line differences are computed by subtractors2203 and 2204 and subsequently mixed by a mixer 2205 corresponding toK_(—)2D signal from the inter-line correlator 2206.

The inter-line correlator 2206 detects the relative chroma correlationbetween the current and next line and current and previous line, suchthat the chroma line comb does not filter across contrasting colourregions. A low pass filter can be applied prior to gradient computationto exclude influence of luminance on chroma signal. The gradients ofcurrent and next line, G_(x,m,m+1), and current and previous line,G_(x,m,m−1), are computed in gradient circuits 2208 and 2209 accordingto the equations (12) and (13) below.

G _(x,m,m+1)=min{max{|C _(x,m+1) −C _(x+1,m) |,|C _(x+1,m+1) −C_(x,m)|},max{|C _(x,m+1) −C _(x−1,m) |,|C _(x−1,m+1) −C _(x,m)|}}  (12)

G _(x,m,m−1)=min{max{|C _(x,m−1) −C _(x+1,m) |,|C _(x+1,m−1) −C_(x,m)|},max{|C _(x,m−1) −C _(x−1,m) |,|C _(x−1,m−1) −C _(x,m)|}}  (13)

They are subsequently filtered by horizontal low pass filters 2210 and2211. The lower the gradient, the higher the correlation, meaning ahigher possibility that the pixels from the two lines belong to the samecolour region. Thus line-comb output from two lines having a lowergradient should have a higher contribution towards the final comb value.K_(—)2D is defined as the weight for the line comb filter between thecurrent and previous chroma line in the function circuit 2212. K_(—)2Dis represented by the equation (14) below.

K _(—)2D=(G′ _(m,m+1))/(G′ _(m,m+1) +G′ _(m,m−1))  (14)

K_(—)2D from the cross chroma suppression circuits 2002 and 2003 can becombined using a max function and upsampled by two or interleaved toprovide the K_(—)2D for the cross luminance suppression circuit 2001.

The output of the line comb filter can be expressed by the equation (15)below.

C _(—)2D=K _(—)2D*(C _(m) −C _(m−1))+(1−K _(—)2D)*(C _(m) −C_(m+1))  (15)

The frame comb adds the previous frame signal C_(m,n−1) from the currentframe signal C_(m,n) using an adder 2213 to generate frame comb output C3D.

The final 3D value, C_(out) is generated via a mixer circuit 2214 usingmotion value, Kmotion from the baseband motion detector 2004 and clippedto valid pixel range with a saturation circuit 2216. C_(out) can berepresented by the equation (16) below.

C _(out) =K_motion*C _(—)2D+(1−K_motion)*C _(—)3D  (16)

Referring to FIG. 7, there is provided a functional block diagram of avideo signal processing system in accordance with one embodiment of thepresent disclosure. The signal processing system 4000 comprises a frontend digital decoder 4001 and a baseband YC separation module 4007. Thefront end digital decoder 4001 decodes the composite input signals togenerate component Y, U and V signals. The decoder 4001 comprises asynchronization unit 4002 to capture the video synchronization signalsand to lock the system clock to the frequency and phase of the incomingsignal using the chroma burst, an input sample rate converter 4003 tore-sample the acquisition sample rate of 27 MHz to four times thesub-carrier frequency, a YC separation circuit 4004 to separate chromaand luminance signal from the composite signal, a chroma demodulator4005 to demodulate the chroma signal according chroma phase lock loop,an output sample rate convertor and scaler 4006 to re-sample theseparated signals to output sampling rate domain and to scale the videosignal to required dynamics.

The component signals from the decoder 4001 are input to the baseband YCseparation circuit 4007 for further 3D comb filtering. The baseband YCseparation circuit 4007 as described above is a second separationcircuit in the signal processing system to compensate for inefficiencyof the first separation circuit 4004 and to eliminate residual crosscomponent signals. As such, the operation of the first separationcircuit 4004 in composite domain may be simplified. In one embodiment,the baseband YC separation circuit 4007 may be a 3D comb filter using amix of frame comb and line comb controlled by a motion detector. Inanother embodiment, the baseband YC separation circuit 4007 may be a 2Dcomb filter with a 3-line comb controlled by an inter-line correlator.In another embodiment, the baseband YC separation circuit 4007 may be aset of complementary or non-complementary filters around the chromasubcarrier frequency with band-stop or notch filter for the Y output andband-pass filter for the C output. In yet another embodiment, the inputis bypassed for the Y output and band-pass filtered for the C output.The baseband YC separation circuit should operate independent of thefront-end separation circuitry and the motion detector should performprecise motion detection regardless of source input.

Now there is provided a detailed description of the motion detectionsystem and baseband YC separation circuitry and signal processing systemfor PAL standard. Referring to FIG. 8, there is provided a functionalblock diagram of the circuitry of the motion detection system for thePAL standard in accordance with one embodiment of the presentdisclosure. As shown in FIG. 8, the motion detection system 1100comprises a luminance motion detector 1101 that detects low frequencyluminance motion between frames n and n−2; chrominance motion detectors1102 and 1103 that detect U and V chroma motion between frames n andn−2; smoothness detectors 1104 and 1105 that detect presence ofluminance residue on U and V chroma components in frames n and n−2;phase motion detectors 1106 and 1107 that detect average luminance andchroma motion between frames n, n−2, n−3, n−4 and n−5; and a chromamotion combiner 1108 that integrates the motion derived from U and Vcomponents. The motion detection system 1100 further comprises a maxcircuit 1606, a saturation circuit 1607, and a 5H-max circuit 1608,which functions will be described hereinafter.

The motion detector system 1100 for the PAL standard has a similararchitecture of the motion detector system 100 for the NTSC standard.But the motion detector system 1100 uses previous frame n−2 instead ofn−1, previous line signals Y_(m−2,n), C_(m−2,n) instead of Y_(m−1,n),C_(m−1,n) and next line signals Y_(m+2,n), C_(m+2,n) instead ofY_(m+1,n), C_(m+1,n) for luminance motion detector, chrominance motiondetectors and smoothness detectors and computation specific to phaserelationships of the standard in phase motion detector.

Referring FIG. 9, there are provided exemplary electric circuitries forthe luminance motion detector 1101, the chrominance motion detectors1102/1103, the smoothness detectors 1104/1105, and the phase motiondetectors 1106/1107 in accordance with one embodiment of the presentdisclosure.

The luminance motion detector 1101 receives three line signals from eachof the current frame n and previous frame n−2. For the current frame n,the three line signals include the next line signal Y_(m+2,n), currentline signal Y_(m,n), previous line signal Y_(m−2,n) via 4 luminance linedelay memories. A vertical low pass filtering 1201 with coefficients [12 1]/4 is performed to cancel out-of-phase chroma signal to generateline-comb signal YLC_(n). Concurrently, for the previous frame n−2, thethree line signals include the next line signal Y_(m+2,n−2), currentline signal Y_(m,n−2) and previous line signalY_(m−2,n−2, via two luminance frame delay memories and four additional luminance line delay memories. Similarly, a vertical low pass filtering 1202 is performed to generate line-comb signal YLC)_(n−2). The line-comb signals YLC_(n) and YLC_(n−2) may alternatively bethe output of line combs of the baseband circuitry.

These line-comb signals YLC_(n) and YLC_(n−2) are then subtracted by asubtractor 1203. The horizontal low pass filter 1204, with low passfrequency characteristics not exceeding the lower end of the overlappingfrequency band of chroma and luminance signal or band-stop frequencycharacteristics covering the chroma band, subsequently filters theline-comb signal differences to exclude possible interference of chromaresidue. The magnitude is extracted by absolute circuit 1205 and passedthrough coring circuit 1206 to eliminate possible noise interference.Finally, it is multiplied by gain, YGain (GJ) via multiplier 1207 andclipped by saturation circuit 1208 to appropriate motion range togenerate low frequency luminance motion YM.

Similar to the luminance motion detector 1101, the chrominance motiondetector 1102/1103 receives three line signals from each of the currentframe n and previous frame n−2. For the current frame n, the three linesignals include the next line signal C_(m+2,n), current line signalC_(m,n), previous line signal C_(m−2,n) via four chroma line delaymemories. A vertical low pass filter 1301 with coefficients [1 2 1]/4 isused to cancel out-of-phase luminance signal to generate line-combsignal, CLC_(n). Concurrently, for the previous frame n−2, the threeline signals include the next line signal C_(m+2,n−2), current linesignal C_(m,n−2), previous line signal C_(m−2,n−2), received via twochroma frame delay memories and four chroma line delay memories, whichare vertically filtered by a vertical low pass filter 1302 to generateline-comb signal CLC_(n−2). The signals CLC_(n) and CLC_(n−2) may befrom the output of line combs in a baseband circuitry described indetail hereinafter.

These line-comb signals CLC_(n) and CLC_(n−2) are then subtracted by asubtractor 1303. Its magnitude is extracted by an absolute circuit 1304to generate intermediate chroma motion CDp and low pass filtered by ahorizontal low pass filter 1305 to smoothen transitions and passedthrough a coring circuit 1306 to eliminate possible noise interference.Finally, it is multiplied by gain, CGAIN (G2) via a multiplier 1307, andclipped by a saturation circuit 1308 to appropriate motion range togenerate chroma motion CD.

The smoothness detectors 1104 and 1105 detect the presence of luminanceresidue and invalidate or override the output of respective chrominancemotion detectors. The smoothness detectors 1104/1105 include bothforward and backward diagonal contributions. The line signals of currentand previous frames are diagonally filtered by forward diagonal highpass filters 1401/1402, and backward diagonal high pass filters1403/1404 with common coefficients [−1 2 −1]/4. It receives the sameinput as the chrominance motion detector with three line signals fromthe current frame n: next line signal C_(m+2,n), current line signalC_(m,n), previous line signal C_(m−2,n) and three line signals from theprevious frame n−2: next line signal C_(m+2,n−2) current line signalC_(m,n−2), previous line signal C_(m−1,n−2).

The line signals of current and previous frames are diagonally filteredby forward diagonal high pass filters 1401 and 1402, and backwarddiagonal high pass filters 1403 and 1404 with common coefficients [−1 2−1]/4. The input vector for forward diagonal contribution is[C_(x−2,m+2) C_(x,m) C_(x+1,m−2)] while the input vector for backwarddiagonal contribution is [C_(x−1,m−2) C_(x,m) C_(x+1,m+2)]. The forwarddiagonally filtered signals are subtracted by a subtractor 1405 and itsmagnitude is extracted by an absolute circuit 1407. The backwarddiagonally filtered signals are subtracted by a subtractor 1406 and itsmagnitude is extracted by an absolute circuit 1408. The max circuit 1409selects the maximum of the forward or backward contribution to generateintermediate high frequency signal CFp. The signal is filtered by ahorizontal low pass filter 1410 to smooth transitions and then cored bya coring circuit 1411 to eliminate small noise. A gain SmoGain (G3) ismultiplied to the filtered output and signal is then clipped by asaturation circuit to generate high frequency signal CF. Alternatively,circuits 1410-1413 may be replaced by binary thresholding circuit tooutput 0 in presence of flat region and 1 in presence of luminanceresidue.

The phase motion detectors 1106/1107 complement the above detectors bydetecting mainly chroma motion in the presence of luminance residue andhigh frequency luminance motion. Each receives the current frame signal,C_(m,n), and a plurality of previous frame signals C_(m,n−1), C_(m,n−2),C_(m,n−3) and C_(m,n−4), via four chroma frame delay memories. Then eachcomputes intermediate motion values YCDp via a circuit 1501 according tothe equation (17) below.

YCD_(p)=max{|C _(m,n) −C _(m,n−1) +C _(m,n−2) −C _(m,n−3) |,|C _(m,n−1)−C _(m,n−2) +C _(m,n−3) −C _(m,n−4)|}  (17)

The first component detects average chroma and luminance motion forplurality of frames from n to n−3 while the second component detectsaverage chroma and luminance motion for plurality of frames from n−1 ton−4. As each component is asymmetrical about the temporal center, anyscene change or chroma motion only occurring between second and thirdframe is not detected. Thus, a second component guarantees full motiondetection.

The motion values may be smoothed by a horizontal low pass filter 1502and cored through a coring circuit 1503. It may be scaled by gainPhaseGain (G4) via a multiplier 1504 and clipped by a saturation circuit1505 to generate YC motion signal, YCD.

The same phase motion detectors 1106/1107 may be applied on theluminance component to generate YC motion values according to theequation (18) below.

YCD_(p)=max{|Y _(m,n) −Y _(m,n−1) +Y _(m,n−2) −Y _(m,n−3) |,|Y _(m,n−1)−Y _(m,n−2) +Y _(m,n−3) −Y _(m,n−4)|}  (18)

In this case, the phase motion detector can complement detection of highfrequency luminance that may not be present as luminance residue inchroma signal.

The chroma combiner 1108 combines results from independent detectorswith U or V inputs. In the case of 4:2:2 sampling format, the samples ofindependent chroma is half that of luminance. The maximum chroma motionUD and VD is taken and duplicated corresponding to two luminance samplesby a maxD circuit 1601 to give C2D. Similarly, the maximum highfrequency signal UF and VF is taken and duplicated by a maxD circuit1602 to give C2F and the maximum YC motion YUD and YVD is taken andduplicated by a maxD circuit 1603 to give YC2D. The duplicated signalshave the same sample rate as luminance motion.

Signals C2D and YC2D pass through the max circuit 1604 and is furthermodified by the selector 1605. Output from max circuit 1604 is selectedwhen a flat chroma region is detected or C2F=0 and signal YC2D isselected in presence of luminance residue or C2F≠0 to give signal CM.This compensates for undetected chroma motion by phase motion detectordue to averaging effect in phase motion detector. The final motionvalue, K_motion, is derived as the maximum 1606 between the motiondetected from luminance YM and motion detected from chrominance CM,clipped by the saturation circuit 1607, and further processed as themaximum in a 5-pixel horizontal window by the 5H-max circuit 1608.

Referring to FIG. 10, there is provided an exemplary circuit of themotion detector for PAL standard in accordance with another embodimentof the present disclosure. Instead of combining the outputs of U and Vdetectors in the chroma combiner 1108, the intermediate output signalsare combined before the filtering, coring, scaling and saturationprocesses. The detailed description is similar to the one for NTSCstandard described above.

Referring to FIGS. 11 and 12, there are provided exemplary circuitriesof the cross luminance suppression circuit 2001 and cross chromasuppression circuits 2002/2003 in the baseband YC separation circuitry2000 as shown in FIG. 4 for PAL standard in accordance with oneembodiment of the present disclosure. The technical differences betweencircuits for the PAL and NTSC lie in the use of next line signal m+2instead of m+1 and previous line signal m−2 instead of m−1 for line comband previous frame signal n−2 instead of n−1 and in the design ofwideband and narrow band filters for chroma subcarrier at 4.43 MHzinstead of 3.58 MHz. Since the operation of the circuitry remains thesame, detailed description of cross luminance suppression circuit 2001and cross chroma suppression circuits 2002 and 2003 for the PAL standardis not provided.

Generally, the disclosure is embedded in a baseband YC separationcircuitry that reduces chroma residue in luminance component andluminance residue in chroma component. A preferred embodiment of thebaseband YC separation circuitry comprises of a line comb filter thatperforms vertical filtering and a frame comb filter that performstemporal filtering. The disclosure is applied as a baseband motiondetector to detect the motion between the candidate frames for temporalfiltering. A mixer selects a high weight on the frame comb when thepixels are detected as stationary or selects a high weight on the linecomb when pixels are detected as moving.

The inputs to the baseband circuitry may be processed by a front enddigital decoder. In this case, the front end digital decoder receivesthe composite signal or s-video signal and decodes it into component Y,U and V signals for processing in baseband. The decoding process mayinclude YC separation with a simple 2D comb filter for example a linecomb, a 3D comb filter for example a line and frame comb controlled by amotion detector, a notch filter for the Y signal and bandpass filter forthe C signal, or simply a demodulation circuitry.

Alternatively, the inputs may be processed by video decoder for examplean MPEG 2 decoder. The inputs to the baseband motion detector may or maynot be pre-processed by the baseband YC separation circuitry. Thus thedisclosure is expected to consider the same variety of inputs as thebaseband YC separation circuitry.

The disclosure operates such that the inputs are not temporally filteredin the presence of motion and temporally filtered in the absence ofmotion, generating clean Y, U and V signals with reduction of crosscolour and dot crawl and ensuring minimally modified signals in theabsence of such artifacts.

It can be applied to a chip or end consumer products like television,display sets, video CD player, DVD players or recorders andset-top-boxes with composite sources or sources that have compositeconversion in at least one stage of processing prior to input. While thepresent disclosure has been described with reference to particularembodiments, it will be understood that the embodiments are illustrativeand that the scope of the appended claims are not so limited.Alternative embodiments of this disclosure have been set forth byimplication and will be apparent to those having ordinary skill in theart to which the present disclosure pertains. Such alternate embodimentsare considered to be encompassed within the scope of one or more of theappended claims. Thus, the scope of this disclosure is described by theappended claims and is supported by the foregoing description. Whilethis detailed description has set forth some embodiments of the presentdisclosure, the appended claims are sufficiently supported to cover andwill cover other embodiments of this disclosure which differ from thedescribed embodiments according to various modifications andimprovements.

1.-41. (canceled)
 42. A baseband YC separation circuitry for videosignal processing, the circuitry comprising: a cross luminance (Y)suppression circuit configured to suppress dot crawl artifacts or chromaresidue present in a Y signal; a cross chroma (U) suppression circuitconfigured to suppress cross colour artifacts or luminance residuepresent in U signals; a cross chroma (V) suppression circuit configuredto suppress cross colour artifacts or luminance residue present in Vsignals; and a baseband motion detector configured to differentiatebetween moving and stationary pixels such that an optimum comb filtercan be selected to maximize effectiveness of YC separation, wherein thebaseband YC separation circuitry is configured to receive Y_(in), U_(in)and V_(in) input signals separately and to output clean luminancesignals Y_(out), U_(out) and V_(out).
 43. The baseband YC separationcircuitry of claim 42, wherein the cross luminance suppression circuitcomprises: an inter-line correlator configured to detect a relativechroma correlation between a current line and a next line and thecurrent line and a previous line, such that a line comb does not filteracross contrasting color regions, the inter-line correlator comprising:a narrowband filter configured to isolate a sub-band of a YC interleavefrequency band; at least one gradient circuit coupled to the narrowbandfilter and configured to compute gradients of the current and nextlines, G_(x,m,m+1), and of the current and previous lines, G_(x,m,m−1);at least one horizontal low pass filter coupled to the gradient circuitand configured to low pass filter for continuity; and a function circuitcoupled to the horizontal low pass filter and configured to generate asignal for a weight K_(—)2D between the current and previous lines; aline comb configured to extract chroma residues from the Y signal, theline comb comprising: a wideband filter configured to filter out low andhigh frequency signals and to retain only a frequency band withinterleave Y and C signal; at least one subtractor configured to computeinter-line differences; and a mixer corresponding to the weight K_(—)2Dsignal from the inter-line correlator and configured to mix inter-linedifferences; a frame comb configured to subtract a previous frame signalY_(m,n−1) from a current frame signal Y_(m,n) using a subtractor togenerate frame comb output; a mixer circuit configured to extract aresidual chroma signal using a motion value, K_motion, from the basebandmotion detector; and a saturation circuit configured to clip an outputof the mixer circuit to defined pixel range so as to generate the cleanluminance signal.
 44. The baseband YC separation circuitry of claim 42,wherein the cross chroma suppression circuits comprise: an inter-linecorrelator configured to detect a relative chroma correlation betweenthe current and next lines and the current and previous lines, theinter-line correlator comprising: at least one gradient circuitconfigured to compute gradients of the current and next lines,G_(x,m,m+1), and of the current and previous lines, G_(x,m,m−1); atleast one horizontal low pass filter configured to subsequently filterthe gradients; and a function circuit configured to generate a weightsignal K_(—)2D between the current and previous chroma lines; a chromaline comb configured to remove the redundant luminance residue from theU_(in) or V_(in) signals, the chroma line comb comprising at least oneadder configured to average inter-line differences and a mixercorresponding to the K_(—)2D signal from the interline correlator andconfigured to mix line comb signal differences; a frame comb configuredto add a previous frame signal C_(m,n−1) to a current frame signalC_(m,n) using an adder to generate a frame comb output C_(—)3D; a mixercircuit configured to use a motion value, K_motion, from the basebandmotion detector to generate a final 3D value, C_(out); and a saturationcircuit configured to clip the final 3D value to a valid pixel range andto output the final 3D value to at least one video processing unit. 45.The baseband YC separation circuitry of claim 42, wherein the basebandmotion detector comprises: a luminance motion detector configured todetect a low frequency luminance motion between a current frame and aprevious frame; at least two chrominance motion detector configured todetect U and V chroma motions between the current frame and the previousframe; a smoothness detector configured to detect presence of luminanceresidue on U and V chroma components in the current frame and theprevious frame; and a phase motion detector configured to detectluminance and chroma motion between the current frame and the pluralityof previous frames.
 46. A video signal processing system used in anelectronic article, the system comprising: a front end digital decoderconfigured to decode a composite input signal to generate component Y, Uand V signals, the front end digital decoder comprising: asynchronization unit configured to capture video synchronization signalsand locking a system clock to a frequency and phase of the input signalusing a chroma burst; an input sample rate converter configured tore-sample a signal sampled at an acquisition sample rate; a YCseparation circuit configured to separate chroma and luminance signalsfrom the composite input signal; a chroma demodulator configured todemodulate the chroma signal according to a chroma phase lock loop; andan output sample rate convertor and scaler configured to re-sample theseparated signals to an output sampling rate domain and to scale anoutput video signal to required dynamics; and a baseband YC separationmodule configured to receive the component signals from the decoder forfurther 3D comb filtering.
 47. The video signal processing system ofclaim 46, wherein the baseband YC separation module comprises a 3D combfilter using a mix of frame comb filtering and line comb filteringcontrolled by a motion detector.
 48. The video signal processing systemof claim 46, wherein the baseband YC separation module comprises a 2Dcomb filter with a 3-line comb filter controlled by an inter-linecorrelator.
 49. The video signal processing system of claim 46, whereinthe baseband YC separation module comprises a set of complementary ornon-complementary filters around a aroma subcarrier frequency with aband-stop or notch filter for a Y output and a band-pass filter for a Coutput.
 50. The video signal processing system of claim 46, wherein thebaseband YC separation module is configured to operate independent offront-end separation circuitry.
 51. The video signal processing systemof claim 46, wherein the electronic article comprises one of atelevision, a display set, a video CD player, a DVD player or recorder,and a set-top-box, and wherein the electronic article is configured toreceive composite sources or sources that have composite conversion inat least one stage of processing prior to input.
 52. A chip comprising acomputer executable medium embedded therein a video signal processingsystem, the system comprising: a front end digital decoder configured todecode a composite input signals to generate component Y, U and Vsignals, the front end digital decoder comprising: a synchronizationunit configured to capture video synchronization signals and to lock thesystem clock to a frequency and phase of the input signal using a chromaburst; an input sample rate convertor configured to re-sample the inputsignal at an acquisition sample rate; a YC separation circuit configuredto separate chroma and luminance signals from the composite signal; achroma demodulator configured to demodulate the chroma signal accordingto a chroma phase lock loop; and an output sample rate convertor andscaler configured to re-sample the separated signals to an outputsampling rate domain and to scale an output video signal to requireddynamics; and a baseband YC separation module configured to receive thecomponent signals from the decoder for further 3D comb filtering,wherein the chip is configured to be used either alone or in conjunctionwith an electronic article.
 53. The chip of claim 52, wherein thebaseband YC separation module comprises a 3D comb filter using a mix offrame comb filtering and line comb filtering controlled by a motiondetector.
 54. The chip of claim 52, wherein the baseband YC separationmodule comprises a 2D comb filter with a 3-line comb filter controlledby an inter-line correlator.
 55. The chip of claim 52, wherein thebaseband YC separation module comprises a set of complementary ornon-complementary filters around a chroma subcarrier frequency with aband-stop or notch filter for a Y output and a band-pass filter for a Coutput.
 56. The chip of claim 52, wherein the baseband YC separationmodule is configured to operate independent of front-end separationcircuitry.
 57. The chip of claim 52, wherein the video signal processingsystem forms a part of one of a television, a display set, a video CDplayer, a DVD player or recorder, and a set-top-box, and wherein thevideo signal processing system is configured to receive compositesources or sources that have composite conversion in at least one stageof processing prior to input.
 58. (canceled)
 59. The baseband YCseparation circuitry of claim 42, wherein the baseband YC separationcircuitry comprises a 3D comb filter using a mix of frame comb filteringand line comb filtering controlled by a motion detector.
 60. Thebaseband YC separation circuitry of claim 42, wherein the baseband YCseparation circuitry comprises a 2D comb filter with a 3-line combfilter controlled by an inter-line correlator.
 61. The baseband YCseparation circuitry of claim 42, wherein the baseband YC separationcircuitry comprises a set of complementary or non-complementary filtersaround a chroma subcarrier frequency with a band-stop or notch filterfor a Y output and a band-pass filter for a C output.
 62. The basebandYC separation circuitry of claim 42, wherein the baseband YC separationcircuitry is configured to operate independent of front-end separationcircuitry.